Lawrence Livermore National Security, LLC

The United States of America As Represented by the Department of Energy

Thomas R Huser

Stephen M Lane

Joe H Satcher, Jr

Christopher W Hollars

Olgica Bakajin

Rodney L Balhorn

Christopher B Darrow

James W Chan

Ted Alfred Laurence

Bradley R Hart

Ronald Li

Chad E Talley

Theodore Zwerdling

John C Rutledge

Douglas S Taylor

Raman spectra of cells, such as normal human T- and B-cells from peripheral blood or human tonsil and the corresponding transformed cells are obtained by optically trapping the cells and obtaining their Raman spectra. The trapped cells can be subjected to one, two, or more different excitation wavelengths, and each wavelength of the corresponding Raman spectra can be stored in a separate channel. In preferred embodiments, two spectra are subtracted from each other to give a difference spectrum and each channel is analyzed independently to characterize the trapped cell. Alternatively, the Raman spectrum can be subjected to Principal Component Analysis (PCA) in order to characterize the trapped cell. The trapped cell thus classified can be sorted, or further manipulated.

Single-cell raman spectroscopy for the non-destructive, non-invasive analysis of cells and cellular components

Surface-Enhanced Raman Spectroscopy (SERS) is a vibrational spectroscopic technique that utilizes metal surfaces to provide enhanced signals of several orders of magnitude. When molecules of interest are attached to designed metal nanoparticles, a SERS signal is attainable with single molecule detection limits. This provides an ultrasensitive means of detecting the presence of molecules. By using selective chemistries, metal nanoparticles can be functionalized to provide a unique signal upon analyte binding. Moreover, by using measurement techniques, such as, ratiometric received SERS spectra, such metal nanoparticles can be used to monitor dynamic processes in addition to static binding events. Accordingly, such nanoparticles can be used as nanosensors for a wide range of chemicals in fluid, gaseous and solid form, environmental sensors for pH, ion concentration, temperature, etc., and biological sensors for proteins, DNA, RNA, etc.

Nanosensors based on functionalized nanoparticles and surface enhanced raman scattering

A method and apparatus with the sensitivity to detect and identify single target molecules through the localization of dual, fluorescently labeled probe molecules. This can be accomplished through specific attachment of the taget to a surface or in a two-dimensional (2D) flowing fluid sheet having approximate dimensions of 0.5 &#x3bc;m&#xd7;100 &#x3bc;m&#xd7;100 &#x3bc;m. A device using these methods would have 10&#x2013;10greater throughput than previous one-dimensional (1D) micro-stream devices having 1 &#x3bc;minterrogation volumes and would for the first time allow immuno- and DNA assays at ultra-low (femtomolar) concentrations to be performed in short time periods (&#x2dc;10 minutes). The use of novel labels (such as metal or semiconductor nanoparticles) may be incorporated to further extend the sensitivity possibly into the attomolar range.

High-throughput, dual probe biological assays based on single molecule detection

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Livermore, CA, United States of America

Thomas R Huser